New York: A new study suggests that mild weather and rain may have helped Genghis Khan, the Mongolian warlord, conquer lands in the 13th century.

The researchers found that the rise of Khan was helped by good weather conditions, abundant rainfall and mild temperatures in central Asia.

The study, led by physical geographer Amy Hessl of West Virginia University and Neil Pederson of Columbia University`s Lamont-Doherty Earth Observatory, was published on Monday in the Proceedings of the National Academy of Sciences.
Because of good weather, grasses grew at a rapid rate, providing fodder for his war horses. It also helped provide food in the way of livestock fed by the bounty.

With the good weather, Genghis Khan united the Mongol tribes to invade and founded a Mongol empire. Thus, the Mongols formed the largest land empire in world history ruling over the modern-day Korea, China, Russia, eastern Europe, India and south-east Asia.

The research shows that the years before Genghis Khan`s rule were characterised by severe drought from 1180 to 1190. Khan`s emergence to power was in 1211 to 1225 A.D and Mongolia saw sustained rainfall and mild temperatures.

“The transition from extreme drought to extreme moisture right then strongly suggests that climate played a role in human events,” study co-author and West Virginia University tree-ring scientist Amy Hessl was quoted as saying to AFP.
“It wasn`t the only thing, but it must have created the ideal conditions for a charismatic leader to emerge out of the chaos, develop an army and concentrate power.

“Where it`s arid, unusual moisture creates unusual plant productivity, and that translates into horsepower. Genghis was literally able to ride that wave.”

In the study, researchers used Siberian pine trees found in the Hangay Mountains in Mongolia. They also used paleoclimatic “proxy” data to theorise the climate of that period since Khan and his armies didn`t carry rain gauges or thermometers as they forayed over the steppes.

The tree rings from those years were “persistently wide,” said Pederson, which he said “suggest that period, climatically speaking, was persistently wet.”

It said the region has warmed rapidly since the mid-20th century and the rings show that recent drought years were the most extreme in more than 1,000-years - possibly a side effect of global warming.

The researchers said that future warming may overwhelm increases in precipitation, leading to similar heat droughts, with potentially severe consequences for modern Mongolia.